--备份
BACKUP DATABASE [库名称] TO DISK='E:\qq\ddd.bak'
--备份并覆盖
BACKUP DATABASE [库名称]  TO DISK='E:\qq\ddd.bak' WITH INIT


--将数据库置于离线状态
ALTER DATABASE [库名称]  SET OFFLINE WITH ROlLBACK IMMEDIATE;
--恢复数据库
RESTORE DATABASE  [库名称]  FROM DISK = 'E:\qq\ddd.bak' WITH REPLACE ;
--将数据库置于在线状态
ALTER DATABASE [库名称]  SET ONLINE WITH ROlLBACK IMMEDIATE;